http://www.einstein-online.info/spotlights/redshift_white_dwarfsAlbert Einstein Institute: "...you do not need general relativity to derive the correct prediction for the gravitational redshift. A combination of Newtonian gravity, a particle theory of light, and the weak equivalence principle (gravitating mass equals inertial mass) suffices. (...) The gravitational redshift was first measured on earth in 1960-65 by Pound, Rebka, and Snider at Harvard University..."

http://adsabs.harvard.edu/abs/2010AAS...21530404H"In January 1924 Arthur Eddington wrote to Walter S. Adams at the Mt. Wilson Observatory suggesting a measurement of the "Einstein shift" in Sirius B and providing an estimate of its magnitude. Adams' 1925 published results agreed remarkably well with Eddington's estimate. Initially this achievement was hailed as the third empirical test of General Relativity (after Mercury's anomalous perihelion advance and the 1919 measurement of the deflection of starlight). It has been known for some time that both Eddington's estimate and Adams' measurement underestimated the true Sirius B gravitational redshift by a factor of four."

http://www.gravityresearchfoundation.org/pdf/awarded/1979/hetherington.pdf"...Eddington asked Adams to attempt the measurement. (...) ...Adams reported an average differential redshift of nineteen kilometers per second, very nearly the predicted gravitational redshift. Eddington was delighted with the result... (...) In 1928 Joseph Moore at the Lick Observatory measured differences between the redshifts of Sirius and Sirius B... (...) ...the average was nineteen kilometers per second, precisely what Adams had reported. (...) More seriously damaging to the reputation of Adams and Moore is the measurement in the 1960s at Mount Wilson by Jesse Greenstein, J.Oke, and H.Shipman. They found a differential redshift for Sirius B of roughly eighty kilometers per second."

http://www.newscientist.com/article/mg16321935.300-ode-to-albert.htmlNew Scientist: "Enter another piece of luck for Einstein. We now know that the light-bending effect was actually too small for Eddington to have discerned at that time. Had Eddington not been so receptive to Einstein's theory, he might not have reached such strong conclusions so soon, and the world would have had to wait for more accurate eclipse measurements to confirm general relativity."

http://www.amazon.com/Brief-History-Time-Stephen-Hawking/dp/0553380168Stephen Hawking: "Einsteins prediction of light deflection could not be tested immediately in 1915, because the First World War was in progress, and it was not until 1919 that a British expedition, observing an eclipse from West Africa, showed that light was indeed deflected by the sun, just as predicted by the theory. This proof of a German theory by British scientists was hailed as a great act of reconciliation between the two countries after the war. It is ionic, therefore, that later examination of the photographs taken on that expedition showed the errors were as great as the effect they were trying to measure. Their measurement had been sheer luck, or a case of knowing the result they wanted to get, not an uncommon occurrence in science."

http://discovermagazine.com/2008/mar/20-things-you-didn.t-know-about-relativity"The eclipse experiment finally happened in 1919 (youre looking at it on this very page). Eminent British physicist Arthur Eddington declared general relativity a success, catapulting Einstein into fame and onto coffee mugs. In retrospect, it seems that Eddington fudged the results, throwing out photos that showed the wrong outcome. No wonder nobody noticed: At the time of Einsteins death in 1955, scientists still had almost no evidence of general relativity in action."